Liquid detergent composition



Unite The present invention relates to cleansers, and more particularly to liquid detergent compositions.

Until recently washday products were sold primarily in particulate form, such as powders, flakes, granules, beads, and the like. Among the major drawbacks to such washday products are the difficulty in obtaining uniform specific gravity of the particles so that measured amounts of the products will have constant detergent power and the likelihood of wastage due to spilling of an opened carton containing the particulate product.

Recently particulate washday products have been replaced to a large extent by liquid detergent products. While liquid detergent compositions do not suffer from the major drawbacks of particulate detergent compositions, they nevertheless introduce problems of their own. Thus, while it is relatively easy to prepare a light duty liquid detergent composition which is homogeneous and hence appealing to the consumer, such products are only useful for light duty work, such as the cleaning of dishes. When one attempts to prepare heavy duty liquid detergent compositions, it is difiicult to obtain products which have homogeneity, because the components of the compositions have a great tendency to separate out from the liquid medium.

While some homogeneous heavy duty liquid detergent compositions have been successfully prepared heretofore, they too suffer from at least two serious drawbacks. For example, some homogeneous heavy duty liquid detergent compositions are only homogeneous because of their high viscosity. The high viscosity, however, renders them difficult to pour and wasteful so that the product tends to adhere to the cap of the container used as a measuring cup or to cling to the inner Walls of the container. Moreover, most homogeneous heavy duty liquid detergent compositions generally have high sudsing power so that they cause suds-lock, especially in a front-loading or horizontal washing machine, which is injurious to the motor of the machine. 1

There is provided in accordance with the present invention a liquid detergent composition which does not suffer from these drawbacks mentioned above. The product of the invention is a liquid detergent composition which is substantiallyhomogeneous, is readily pou'rable, and has heavy duty detergent properties. It is also a low sudsing or intermediate sudsing product so that suds-lock is avoided.

The product of the invention contains five essential components in order to achieve these highly desirable properties. One component is water which serves as a dissolving, suspending, or emulsifying medium for the remaining components in the composition.

A further component is one or more synthetic organic nonionic non-soap detergent used in a total amount from about 7% to about and preferably about 10%, by weight of the composition. These nonionic detergents are well known compounds and in general are condensates of a hydrophobic base, such as the hydrophobic base formed by the condensation of propylene oxide with propylene glycol, alkyl phenols, alcohols, and mercaptans, with several moles of an allzylene oxide, such as ethylene oxide and propylene oxide. Typical examples thereof include the condensate of dodecylphenol with an average of ten moles of ethylene oxide sold under the name Sterox DI, the condensate of nonylphenol with an average of nine moles of ethylene oxide sold under the States atent O name Igepal CO-630, the condensate of nonylphenol with an average of ten moles of ethylene oxide sold under the name Tergitol NPX," the condensate of tridecyl alcohol with an average of ten moles of ethylene oxide sold under the name Sterox A1400, and the polyoxyethylene polyoxypropylene ethanols having the empirical.-

formula HO(C H O),,(C H O) (C H O) H prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer from 26 to 30 and a plus 0 is an integer such that the molecule contains from 0% to 10% ethylene oxide (Pluronic L-60), or from 10% to 20% ethylene oxide (Pluronic L-61), or from 40% .to ethylene oxide (Pluronic L-64). These compounds impart detergent and low sudsing or intermediate sudsing properties to the liquid product.

Another component of the liquid product imparts heavy duty detergent and sequestering properties thereto. This component is potassium pyrophosphate which is present in the liquid product in an amount from about 20% to about 30%, and preferably about 25%, by weight. The remaining two essential components of the liquid product function as binary stabilizing agents for the other components in the aqueous medium. One of these stabilizers is either an interpolymer of vinyl methyl ether and maleic anhydride or a linear copolymer of ethylene and maleic anhydride. The specific viscosity of a 1% solution of the interpolymer in Z-butanone is from 0.8 to 3.5, and preferably from 1.2 to 1.8, while the specific viscosity of a 1% solution of the linear copolymer in dimethyl formamide at 25 C. is from 1.2 to 1.8, and preferably 1.8. The liquid product contains from about 1.5% to about 3%, and preferably about 2%, by weight of the interpolymer or linear copolymer which is present in the final product as an alkali metal salt thereof in view of the alkali in the composition.

The other stabilizer is an alkali metal soap of caprylic acid which has eight carbon atoms in the molecule. In general, it is preferred to use the potassium soap rather than the sodium soap. The soap is present in the composition in an amount from about 2% to about 3%, and preferably about 2%, by weight. The soap can be added to the liquid product either as soap or can be formed in situ by adding the caprylic acid and then saponifying it with the alkali present in the product.

If desired, the liquid product of the invention can contain various compatible adjuvants which do not destroy the basic characteristics of the composition. For example, the product can contain builders, such as alkali metal silicates, which also function as corrosion inhibitors. In general, the product would contain about 3% by weight of sodium or potassium silicate. Also the product can contain solubilizers or hydrotropes, such as sodium xylene sulfonate which is generally present therein in an amount of about 2% by weight. Other suitable compatible adjuvants include very small amounts of fluorescent dyes, colorants, perfumes and soil suspending agents, such as sodium carboxymethylcellulos'e.

The composition of the invention is readily prepared by merely mixing together the components thereof in the aqueous medium.

The composition must contain the essential components mentioned above in order to impart thereto substantial homogeneity, heavy duty properties, ready pourability and controlled sudsing. Not only must these components be present, but also they must be used in the approximate amounts set forth above. I

This is readily demonstrated by the examples set forth below in Table I wherein various essential components were omitted from some formulations; wherein soaps other than alkali metal caprylates were used, such as p0- tassium caproate having six carbon atoms and potassium caprate having ten carbon atoms, in other formulations; and wherein the amounts of the binary stabilizers were altered in other formulations; All of the products set What is claimed is:

1. A substantially homogeneous, readily pourable heavy duty liquid detergent composition consisting essentially of an aqueous emulsion of (1)from about' to about l5% by weight of a synthetic organic nonionic detergent which is a condensate of a hydrophobic base with several moles of ethylene oxide, (2) from about to about by weight of potassium pyrophosphate, (3) about 1.5% to about 3% by weight of a stabilizer selected from the group consisting of (a) an alkali metal salt Potassium pyrophoshate In the examples of Table I above, Sterox DI, Sterox All-100 and Pluronie L-61 have been identified hereinabove. PVM/MA is an abbreviation for the interpolymer of vinyl methyl ether and maleic anhydride. The interpolymer used iii the above examples had a specific viscosity of 1.2-1.8. E/ MA is an abbreviation for the linear copolymer of ethylene and maleic anhydride. The linear copolymer used in the above examples had a specific viscosity of 1.8. The miscellaneous ingredientsv are very small amounts of impurities, dyes, colourants, etc.

Various embodiments of the composition of the invention are illustrated by the examples set forth below in Table II. All of the examples in Table II were substantially homogeneous, i.e., there was either no separation of the components at all or only very slight separation of the components after storing the compositions for two weeks at roomtemperature and at 125 F. Also all of the examples in Table, II had heavy duty properties and were readily pourable' in view of their viscosities of from about 200 to about 700 centipoises (Brookfield Viscosimeter,

No. 3 spindle, 30 r.p.m.). They were further characterized by being either low sudslng or intermediate sudslng so that suds-lockwas avoided.

Table of an interpolymer of vinyl methyl ether and maleic anvhydride, said interpolymer having a specific viscosity of 0.8 to 3.5 asdetermined on a 1% solution thereof in 2- butanone, and (b) an alkali metal saltof a linear copolymer of ethylene and maleic anhydride, said linear copolymer having a specific viscosity of 1.2 to 1.8 as determined on a 1% solution thereof in'dimethyl formamide at 25 C.,' and (4) from about 2% to'about 3% by weight of an alkali metal salt of caprylic acid, said alkali metal cations of components (3) and (4) beingselected from the. group consisting of sodium and potassium cations, and said composition having a viscosity of frorrrabout 200 to about 700 centipoises measured by a Brookfield Viscosimeter, No. 3 spindle, 3O revolutions per minute.

2. A substantially homogeneous, readily pourable, heaxy duty liquid detergent composition as defined by claim 1 which also contains about 3% by weight of an' alkali metal silicate selected from the group consisting of sodium and potassium silicates.

3. A substantially homogeneous, readily pourable, heavy duty liquid detergent composition as defined by claim 1 which also contains about 2% by weight of sodium xylene sulfonate.

Examples Sterox DJ Sterox AJAOO. Igepal C0630 'Iergitol N PX. Pluronie 11-60. Pluronie L-fil Iluronie L-64 Potassium pyrophosphate Sodium pyrophosphate- PVM/MA (Sp. vise. 0.8-1.2). PVM/MA (Sp. vise. 1.2-L8). PVM/MA (Sp. vise. 2.5-3.5).

E/MA (Sp. vise. 1.8) Caprylie acid Potassium hydroxide. Sodium hydroxide Sodium xylene sullonate. Sodium silicate (Na OzsiO mi;

of 122.5) Water and miscellaneous It will be appreciated that various modifications and 4. A substantially homogeneous, readily pourable heavy duty liquid detergent composition consisting essentially of an aqueous emulsion of (1) about 10% I of a synthetic organic nonionic detergent which is a condcnsate of a hydrophobic base with several moles of ethylene oxide, (2) about 25% by weight of potassium pyroby weight phosphate, (3) about 2% by weight of an alkali metal salt of an interpolymer of vinyl methyl ether and maleic anhydride, said interpolymer having a specific viscosity of 1.2 to 1.8 as determined on a 1% solution thereof in Z-butanone, and (4) about 2% by weight of an alkali metal salt of caprylic acid, said alkali metal cations of components (3) and (4) being selected from the group consisting of sodium and potassium cations, and said composition having a viscosity of from about 200 to 'about 700 centipoises measured by a Brookfield Viscosimeter, No. 3 spindle, 30 revolutions per minute.

5. A substantially homogeneous, readily pourable heavy duty liquid detergent composition consisting essentially of an aqueous emulsion of (1) about by weight of a synthetic organic nonionic detergent which is a condensate of a hydrophobic base with several moles of ethylene oxide, (2) about by weight of potassium pyrophosphate, (3) about 2% by weight of an alkali metal salt of a linear copolymer of ethylene and maleic anhydride, said linear copolymer having a specific viscosity of 1.8 as determined on a 1% solution thereof in dimethyl formposition having a viscosity of from about 200 to about.

700 centipoises measured by a Brookfield Viseosimeter, No. 3 spindle, revloutions per minute.

References Cited by the Examiner UNITED STATES PATENTS 2,396,785 3/46 Hanford 2,560,839 7/51 Ayo et a1. 252-109 XR 2,621,169 12/52 Robinette et al. i 252-89 2,702,277 2/55 Kinney 252-89 2,857,365 10/58 Johnson 260-785 2,877,186 3/59 Krumrei 252-438 2,947,701 8/60 Ruff 252-109 3,060,124 10/62 Ginn 252- JULIUS GREENWALD, Primary Examiner. 

1. A SUBSTANTIALLY HOMOGENEOUS, READILY POURABLE HEAVY DUTY LIQUID DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF AN AQUEOUS EMULSION OF (1) FROM ABOUT 7% TO ABOUT 15% BY WEIGHT OF A SYNTHETIC ORGANIC NONIONIC DETERGENT WHICH IS A CONDENSATE OF A HYDROPHOBIC BASE WITH SEVERAL MOLES OF EHTYLENE OXIDE, (2) FROM ABOUT 20% TO ABOUT 30% BY WEIGHT OF POTASSIUM PYROPHOSPHATE, (3) ABOUT 1.5% TO ABOUT 3% BY WEIGHT OF A STABILIZER SELECTED FROM THE GROUP CONSISTING OF (A) AN ALKALI METAL SALT OF AN INTERPOLYMER OF VINYL ETHER AND MALEIC ANHYDRIDE, SAID INTERPOLYMER HAVING A SPECIFIC VOSCOSITY OF 0.8 TO 3.5 AD DETERMINED ON A 1% SOLUTION THEREOF IN 2BUTANONE, AND (B) AN ALKALI METAL SALT OF A LINEAR COPOLYMER OF ETHYLENE AND MALEIC ANHYDRIDE, AND SAID LINEAR COPOLYMER HAVING A SPECIFIC VISCOSITY OF 1.2 TO 1.8 AS DETERMINED ON A 1% SOLUTION THEREOF IN DIMETHYL FORMAMIDE AT 25* C., AND (4) FROM ABOUT 2% TO ABOUT 3% BY WEIGHT OF AN ALKALI METAL SALT OF CAPRYLIC ACID, SAID ALKALI METAL CATIONS OF COMPONENTS (3) AND (4) BEING SELECTED FROM THE GROUP CONSISTING OF SODIUM AND POTASSIUM CATIONS, AND SAID COMPOSITION HAVING A VISCOSITY OF FROM ABOUT 200 TO ABOUT 700 CENTIPOISES MEASURED BY A BROOKFIELD VISCOSIMETER, NO. 3 SPINDLE, 30 REVOLUTIONS PER MINUTE. 